Powersuits you sir: wearable exoskeleton technology

With the news that an engineering student from Kerala, India, has developed a fully-functioning wearable exoskeleton, we go to Hollywood and beyond for a look at this most revolutionary of tech.

Mechanical engineering student Vimal Govind Manikandan has set Marvel legend turned Hollywood creation into striking reality and built himself a fully functioning, wearable exoskeleton capable of lifting weights of up to 150kg.

Inspired, in part, by the creative genius of Tony Stark’s Iron Man, the Calicut University student set about turning imaginative whimsy into authentic wearable metal and has become something of a social media star in the process. Drawing on his extensive engineering knowledge and with a little help from the Internet, Manikandan’s suit is an hydraulics-powered exoskeleton employing mechanical systems, actuators, micro controllers and force sensors to produce movement.

Writing in a past issue of the International Journal of Mechanical Engineering and Robotics Research, Manikandan describes how the user is attached to the exoskeleton using links and sockets, with pressure sensors located at the sockets to sense body movements. The suit’s first prototype proved the system was stable and able to walk on two feet. It also allowed space for an on-board engine, together with its different subsystems such as cooling system and fuel system, to be added in future, without losing its centre of gravity point.

The student was also heavily influenced by the exoskeleton suits depicted in Avatar, donned by the humans to work, fight and generally stomp about throughout the rainforests of Pandora. The film’s armoured Amplified Mobility Platform (AMP) suits featured enclosed cockpits from within, which the movements of the user’s arms and legs are translated to the suit's exterior limbs. The suit then ‘amplified’ the movements such that a small lift of the arm translated into a correspondingly giant arc of the AMP’s huge metal arm.

When it comes to exoskeletons, director and writer James Cameron has form, and, indeed, Manikandan’s first prototype is not unlike the power loader used by Ripley in Cameron’s Aliens as she grapples with the Queen (Giger’s alien, not our dear HRH) in order to save Newt and exit the USS Sulaco. The power loader here is a commercial, mechanised exoskeleton equipped with hydraulic ‘claws’ to manipulate and lift a variety of heavy materials and objects.

Real-life work in the realms of exoskeleton technology continues to progress, with developers in the fields of industrial, defence and medical applications, gaining ground in leaps and hydraulically-powered bounds. Global security and aerospace company Lockheed Martin continues to develop Fortis, an unpowered, lightweight exoskeleton developed to improve endurance and safety in industrial settings.

Daily industrial work can be physically exhausting with workers often using heavy, hand-operated tools. That’s where exoskeleton technology comes in, as Patricia Aelker, programme manager of Lockheed Martin’s exoskeleton technologies, explains.

“Exoskeletons can enhance a person’s physical capabilities. To increase strength or endurance, you must have a keen understanding about the structure of the human body, the science of how the body moves and the variations among individuals.”

Using that information, the team developed the Fortis exoskeleton, to take the weight of a load, like a heavy hand tool or an alien, off operators, making it easier for them to do their work. Using the principles of biomechanics, the weight is transferred to a mechanical arm and down to the ground through a series of joints, similar to the joints in your hips, knees and ankles. Reducing the load and impact from operators translates into productivity gains.

“When you hold a tool, you’re not only carrying its weight, but also enduring the impact of using it,” Aelker said. “When wearing the Fortis exoskeleton, a user only needs to guide the tool to the location where it should be used. It feels like you’re using the tool in an almost weightless environment.”

Many of the current commercial exoskeletons are rooted in military exoskeleton technology research. For decades, the US military has been looking into powered exoskeleton suits allowing soldiers to carry heavy equipment and really big guns.

Future Soldier was a multi-nation military project by the United States and its allies launched in the late 1990s seeking to gain superiority to enemy ground forces through the radical use of technologies such as nanotechnology, powered exoskeletons and magnetorheological fluid-based body armour. The vision was to equip the average ground-based combat soldier with an integrated set of high-technology uniforms and equipment, linked to an array of real-time and archived battlefield information resources. In early 2016, the Future Soldier project was shelved and stopped receiving funding due to budget cuts.

However, back in 2001, the US Army's research and development branch, DARPA (Defense Advanced Research Projects Agency) had unveiled two exoskeleton programmes. It had, in fact, been working away on a design for a powered military exoskeleton proposed by Sarcos Inc, since 2000. The Sarcos suit is powered by a single engine, including a tank holding 24 hours of fuel, that sits near the wearer's be-muscled buttocks. Called the XOS Exoskeleton, the suit gives the wearer increased strength and endurance through servo motors powered by the engine and purportedly enables wearers to lift nearly 100kg.

Initial production models of the XOS are to be used for logistics and supply tasks such as repetitive lifting of heavy objects, with future models including combat customisations for firing heavy weapons or transporting wounded soldiers. A second iteration, the Raytheon Sarcos XOS 2, was released in 2010.

In addition, working in partnership with US Special Operations Command, DARPA had also, in 2013, started work on a super-soldier suit called TALOS (Tactical Assault Light Operator Suit), supposedly unlike anything in the history of warfare. Engineered with full-body ballistics protection, integrated heating and cooling systems, embedded sensors, antennas, and computers, with 3D audio and optics for vision in various light conditions, this all-singing-all-dancing power suit – something akin to Cameron’s AMP suits in Avatar - also has life-saving oxygen and haemorrhage controls, and aims to be fully functional by 2018.

“I am here to announce that we are building Iron Man,” US President Barack Obama said of the suit during a manufacturing innovation event in 2014.

Meanwhile, Japanese researchers at a company called Cyberdyne - a name shared by the fictional firm that creates Skynet in Cameron's Terminator franchise - have invented Iron Man-style body casing for medical use, named Robot Suit Hybrid Assistive Limb, or HAL – a nod to Arthur C. Clarke’s sentient computer in his Space Odyssey series?

HAL treated its first patient last month after gaining medical device approval under the new classification of ‘Bio-signal-responsive motor function improvement device’, for the treatment of patients suffering from slowly progressive rare neuromuscular diseases at the Niigata National and Tokushima hospitals. HAL for Medical Use (lower limb type) is hailed as the world’s first robotic treatment device built for delaying the advancement of such diseases.

When a wearer intends to move his or her body, various signals are sent from the brain to the muscles through the nerves, but any impairments to this process disturb the motion of the musculoskeletal system. Those signals, however, leak onto the skin surface as bio-electric signals (BES) which are read by HAL. The power units of HAL are activated according to this BES and other information obtained from its many sensors, allowing the device to realise the movements of the lower limbs as intended by the user. There are three control modes which can be adjusted at each joint, in various combinations allowing for customisation according to the wearer’s condition.

According to neurologist and deputy director of the Niigata National Hospital, Dr Takashi Nakajima; “Until now, there were no treatment methods for patients with these rare neuromuscular diseases, but this break-through technology gives us a new avenue for treatment. I want to continue advancing efforts to expand the target diseases, so that patients with other diseases can benefit from HAL.”

Another contender in the medical field is SuitX, founded in 2012 by University of California, Berkeley, Professor Homayoon Kazerooni and former graduate students of the university’s Human Engineering and Robotics Laboratory. Called Phoenix, its exoskeleton weighs in at 27 pounds and costs $40,000, about half the weight and price of some of its competitors. This low-profile custom-fit robotic suit allows users to experience walking by returning movement to wearers’ hips and knees with small motors attached to standard orthotics.

Although you could say, in all seriousness, that the sky really is the limit when it comes to exoskeleton technology (I’m basing this on the fact that Iron Man can fly), one very real hurdle to overcome in the relentless pursuit of human augmentation, is the search for a suitable power source that lasts more than the current few hours.

Unless a real-world team out there has re-created Tony Stark’s Arc Reactor in all its donut-shaped power core of glory, exoskeleton technology is currently constrained by the limitations of battery power and the space restrictions and weight of packing an engine. However, if we’re to base technological advances on the best known and most widely cited of Arthur C. Clarke’s prediction-related three laws, that ‘any sufficiently advanced technology is indistinguishable from magic’, then look no further than the Tokamak.

A device invented in the 1950s by Soviet physicists Igor Tamm and Andrei Sakharov, the Tokamak uses a powerful magnetic field to confine plasma in the shape of a torus to create energy. Experimental Cold War-era Soviet fusion reactor it may be, but with today’s modern superconductors creating some of the most powerful electromagnets in existence, perhaps the reality of the Arc Reactor is only a scaled-down step away?

Easier said than done, for sure, but if the second of Arthur C. Clarke’s three laws holds true, then ‘the only way of discovering the limits of the possible is to venture a little way past them into the impossible’.

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